As location-aware and pervasive computing technologies become more prevalent, privacy concerns are becoming increasingly more important. User preferences about location privacy may depend on <it>place</it>, not only in terms of their physical location but also in terms of their <it>social context</it>: how they define where they are, what they are doing, and whom they are with at the time. Using the experience sampling method, the authors explored the privacy preferences of 25 users during one week. They found that participants were more willing to share location information when at home or alone than when at other locations or with friends. Most participants were consistent in their location privacy preferences across requester categories and regardless of place. Some participants, however, varied in their willingness to share location information depending on where they were, who they were with, and who was requesting the information. Those participants tended to be more concerned about privacy in general. These findings are useful for designing future privacy policies and user interfaces for pervasive computing. This article is part of a special issue on security and privacy.